The present application relates to a semiconductor structure and a method of forming the same. More particularly, the present application relates to a semiconductor structure including a fin field effect transistor device having a flash (i.e., nonvolatile) memory of high-density and a method of forming such a semiconductor structure.
For more than three decades, the continued miniaturization of metal oxide semiconductor field effect transistors (MOSFETs) has driven the worldwide semiconductor industry. Various showstoppers to continued scaling have been predicated for decades, but a history of innovation has sustained Moore's Law in spite of many challenges. However, there are growing signs today that metal oxide semiconductor transistors are beginning to reach their traditional scaling limits. Since it has become increasingly difficult to improve MOSFETs and therefore complementary metal oxide semiconductor (CMOS) performance through continued scaling, further methods for improving performance in addition to scaling have become critical.
The use of non-planar semiconductor devices such as, for example, semiconductor fin field effect transistors (finFETs) is the next step in the evolution of complementary metal oxide semiconductor (CMOS) devices. Semiconductor fin field effect transistors can achieve higher drive currents with increasingly smaller dimensions as compared to conventional planar FETs. Employment of finFETs in semiconductor devices requires different semiconductor processing steps than planar FETs, and therefore, a flash memory (i.e., nonvolatile) device having a manufacturing sequence that is compatible with a manufacturing sequence of finFETs is needed. Flash memory is commonly used in mobile devices, personal computers, servers, digital audio players, digital cameras, synthesizers and video games.